Hiding synchronous vs. asynchronous with higher-order functions means doing it with callbacks. It's generally hard to take a function that was originally writte

Hiding synchronous vs. asynchronous with higher-order functions means doing it with callbacks. It's generally hard to take a function that was originally written to run synchronously and change it to run asynchronously without changing the way it's called. I don't see this as world-changing either, but I understand why people like it.